Fast and Distributed Power Control Algorithm in Underlay Cognitive Radio Networks

—The power allocation in an underlay cognitive radio network rises up several challenges due to rapid utilization of the available spectrum hole. In this paper, we propose a noncooperative power-game algorithm to solve the power allocation problem in an underlay cognitive radio network with two main objectives: (i) to provide good quality of service to cognitive radio nodes, and (ii) to protect the transmission of primary users from the interference generated by nearby cognitive radio. These objectives have been assured by including the following constraints: transmit power on each cognitive node, acceptable aggregate interference at the primary’ receiver and quality of service at the cognitive radio’ receiver. Simulation results show that the proposed algorithm is more convenient in the distributed manner because of its faster convergence in terms of power and the received SINR. Cheating scenario has been tested as well. Moreover, existence and uniqueness for the Nash Equilibrium have been proved mathematically and by simulation as well.